After a recent maintenance job on my DB89 I checked my loco yesterday and found. what I thought, was too much oil on the gears. So I mopped it all up with a tiny tissue pad, moistened in very volatile degreasing solvent and got everything nice and clean. When I put it back together I found it ran MUCH hotter than it did before. Used to be rather warm but now it's very hot. I immediately stopped running. I have lubricated the top motor bearing very recently too. Any thoughts? I think I cleaned up a bit too well. I plan to carefully reapply fresh oil. I plan to also clean the brushes and commutator again, and wheel contacts. This is the first time I have seen it get this hot.

Still trying to get used to this tiny thing....

Running hot tends to indicate something causing a short-circuit leading to the overheating.

One immediate thought, in light of your 'very volatile' solvent comment - the motor armature windings are extremely fine copper wire, coated in an equally fine lacquer to prevent the coils from contacting each other and shorting out.

There's a chance your volatile solvent has partially disolved the lacquer, and it may have dramatically altered the resistance of the windings. The only real way you'd know this is by taking a resistance reading of each coil from the armature, and compare with an identical one.

However, if the entire motor is otherwise clean, and freshly re-oiled, and it's still running hot, I suggest the armature is toast and will need to be replaced.

Either there's a mechanical bind of some sort or an electrical issue causing the motor to draw a lot more current than normal. Something may be just slightly out of place.

They are a very simple design with little that can go wrong, did you refit the small condensor ok?

I've attached a parts view if it helps.

Regards

Steve
NZ

"There's a chance your volatile solvent has partially disolved the lacquer"

No I am very sure that it never got that far inside. Just a slightly moistened tissue pad was used.

Ok all good, I had wondered if you had soaked the armature to clean it - I think a light once over with a tissue is hardly likely to have done it - but just thinking it through does it seem at all jerky in operation? - if one of the windings was damaged, it will effectively run at 2/3rd's and sometimes not even start, and stall at low speeds. Kind of like if you can imagine a car engine running with one spark plug out - will run, but you wouldn't want to drive it.

But before worrying about anything like that and over-thinking it, just disassemble again, check all parts for free movement and no contamination, reassemble, smallest drop of oil and report

OK I think I found the cause of my problems. When I took the bottom plate off I did not realise the wheels could move enough to allow the contactors to slip out from behind the wheels..well they can and they did...so a lot of the contactors were in front of the wheels making very poor contact if at all. I have it all in piceces now (not that i really wanted to) and I think I can get it all back together but will need some new brushes since one of them fell apart when I took it off to clean them. If the carbon head was not properly attached this might have also contributed to the high resistance and thus high current too.

I def. have a 5 pole motor so any suggestions for where to get them?

Thanks

Much wiser now..not by choice though...

I need these according to my manual:

http://www.ebay.com/itm/EE-090-...lub-5-pole-/230522187829

"Isn't it fun learning as you go? This forum has your back though don't forget. Great support group! It makes all the difference. "

Thanks...

Hi. Shipping costs will always be a problem.
That little loco is a real workhorse. Just needs a bit more attention. The age doesn't really seem to make much difference it is so well engineered.

If you go to put it back together and find out some of the parts are too badly damaged you could try this site for possibly cheaper used but acceptable parts:

http://www.ersatzteile-1...8a8617b7b65dc0cda940ac13

Just use Google Chrome or translator on the website and it is possible you can find what you need. Someone in this forum provided me with this site and my experience was very good. They take PayPal too. Just watch that darn exchange rate. There is always something... You know how that goes.

Best wishes

Dwight

I thought it would help others to detail my mistakes so here goes:





#1 - If you remove the bottom plate to access gears, even if you don't take them out, it is possible for the wheels to move sufficiently so that the contact strips come out from behind the wheels and go in front which is wrong. I only noticed when I expanded this photo.





#2 The head fell out of one of my brushes. I am not sure if this caused an over heat or vice versa. new ones on order. I saw no way to fix it back...looks like it was a squeeze fit.

Edited by user 12 May 2014 04:39:03(UTC)  | Reason: Not specified

OK the new brushes arrived. They look quite different to the ones that came off..in a good way. They are welded or soldered in. Old one seemed to be just crimped. They did have some green stuff on them though.



I fitted them and did some more cleaning and adjusting. It was a bit hesitant at first and I have removed the brushes a couple of time to clean again the commutator in case there is still a bit of excess oil floating around.

Right now it seems to be running quite nicely, not getting more than warm and no big fat orange sparks as before.

I am running it for a few days with the body off in case I need a few more cleans. I agree, I think a bit too much oil..and it ran down the shaft..but the old brushes may have contributed to the problem if the carbon block is not firmly in place to make a good electrical connection.